Abstract

BACKGROUND: Increasing prevalence of multiple antibiotic resistance in Klebsiella pneumoniae strains confines the therapeutic options used to treat bacterial infections. OBJECTIVE: We aimed in this study to investigate the role of AcrAB, qepA efflux pump, and AAC(6')-Ib-cr enzyme in ciprofloxacin resistance and to detect the RAPD-PCR fingerprint of K. pneumoniae isolates. METHODS: In total, 117 K. pneumoniae isolates were collected from hospitalized patients in three hospitals in Tehran, Iran from August 2013 to March 2014. Antimicrobial susceptibility tests were performed by the disk diffusion method. Molecular identification and expression level of encoding quinolone resistance genes, acrA, acrB, qepA, and aac(6')-Ib-cr, was performed by PCR and real-time PCR assays, respectively. All the K. pneumoniae isolates containing these genes was used simultaneously for RAPD-PCR typing. RESULTS: Colistin and carbapenems were the most efficient antibiotics against the clinical isolates of K. pneumoniae. PCR assay demonstrated that among the 117 isolates, 110 (94) and 102 (87) were positive for acrA and acrB gene, and for qepA and aac(6')-Ib-cr genes, 5 (4) and 100 (85) isolates were detected, respectively. Determination of AcrAB pump expression in 21 of strains demonstrated an increased expression, and the mean increase expression for acrB genes was 0.5-81. The results of RAPD-PCR reflected that in 95 CI, all isolates belong to a clone. CONCLUSION: A high prevalence of genes encoding quinolone resistance in K. pneumoniae was detected in clinical samples. Therefore, control of infection and prevention of drug-resistant bacteria spread need careful management of medication and identification of resistant isolates.